Recessed light fixtures typically include a housing affixed to, and extending into, a ceiling, wall, or other such structure, a trim mounted to the housing, and a lamp socket extending through an opening in the inner wall of the housing. A standard trim includes a laterally outwardly projecting trim ring at its outer end for engaging the structure surface in order to cover the edge of a hole in the structure through which the trim extends.
Recessed light fixtures, mounted in holes formed in ceilings or walls, represent a potential source of air exchange between the heated (or air conditioned) living space below the ceiling and the non-climate controlled spaces beyond the ceiling and walls. Gaps between the trim ring and the ceiling hole, and seams or openings in the housing may provide primary leak paths in a conventional recessed lighting fixture.